Application: kwin_x11 (5.14.5)

Qt Version: 5.12.1
Frameworks Version: 5.54.0
Operating System: Linux 4.20.6-arch1-1-ARCH x86_64
Distribution: "Arch Linux"

-- Information about the crash:
- Unusual behavior I noticed:
when i use opengl-2 , it broke serveral times before i can use it

The crash can be reproduced sometimes.

-- Backtrace:
Application: KWin (kwin_x11), signal: Segmentation fault
Using host libthread_db library "/usr/lib/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f4e94121840 (LWP 1711))]

Thread 6 (Thread 0x7f4df8406700 (LWP 1763)):
#0  0x00007f4e9a8f1afc in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f4df89e0be4 in  () at /usr/lib/dri/i965_dri.so
#2  0x00007f4df89e0908 in  () at /usr/lib/dri/i965_dri.so
#3  0x00007f4e9a8eba9d in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f4e9d17ab23 in clone () at /usr/lib/libc.so.6

Thread 5 (Thread 0x7f4e81f65700 (LWP 1725)):
#0  0x00007f4e9a8f1afc in pthread_cond_wait@@GLIBC_2.3.2 () at /usr/lib/libpthread.so.0
#1  0x00007f4e9b5f228c in  () at /usr/lib/libQt5Script.so.5
#2  0x00007f4e9b5f22a9 in  () at /usr/lib/libQt5Script.so.5
#3  0x00007f4e9a8eba9d in start_thread () at /usr/lib/libpthread.so.0
#4  0x00007f4e9d17ab23 in clone () at /usr/lib/libc.so.6

Thread 4 (Thread 0x7f4e831a6700 (LWP 1723)):
#0  0x00007f4e9d16fd16 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f4e9bd16bab in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f4e9bd1808b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f4e9bcc3b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f4e9bb07569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f4e9a0a9969 in  () at /usr/lib/libQt5Qml.so.5
#6  0x00007f4e9bb0896c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f4e9a8eba9d in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f4e9d17ab23 in clone () at /usr/lib/libc.so.6

Thread 3 (Thread 0x7f4e923b4700 (LWP 1716)):
#0  0x00007f4e9d16fd16 in ppoll () at /usr/lib/libc.so.6
#1  0x00007f4e9bd16bab in qt_safe_poll(pollfd*, unsigned long, timespec const*) () at /usr/lib/libQt5Core.so.5
#2  0x00007f4e9bd1808b in QEventDispatcherUNIX::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#3  0x00007f4e9bcc3b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#4  0x00007f4e9bb07569 in QThread::exec() () at /usr/lib/libQt5Core.so.5
#5  0x00007f4e99b0eba6 in  () at /usr/lib/libQt5DBus.so.5
#6  0x00007f4e9bb0896c in  () at /usr/lib/libQt5Core.so.5
#7  0x00007f4e9a8eba9d in start_thread () at /usr/lib/libpthread.so.0
#8  0x00007f4e9d17ab23 in clone () at /usr/lib/libc.so.6

Thread 2 (Thread 0x7f4e933c5700 (LWP 1714)):
#0  0x00007f4e9d16fc21 in poll () at /usr/lib/libc.so.6
#1  0x00007f4e9ba2c630 in  () at /usr/lib/libxcb.so.1
#2  0x00007f4e9ba2e2db in xcb_wait_for_event () at /usr/lib/libxcb.so.1
#3  0x00007f4e938cd949 in  () at /usr/lib/libQt5XcbQpa.so.5
#4  0x00007f4e9bb0896c in  () at /usr/lib/libQt5Core.so.5
#5  0x00007f4e9a8eba9d in start_thread () at /usr/lib/libpthread.so.0
#6  0x00007f4e9d17ab23 in clone () at /usr/lib/libc.so.6

Thread 1 (Thread 0x7f4e94121840 (LWP 1711)):
[KCrash Handler]
#6  0x00007f4e9cebc8f2 in KWin::Workspace::clientArea(KWin::clientAreaOption, int, int) const () at /usr/lib/libkwin.so.5
#7  0x00007f4e9cea6c60 in KWin::Client::manage(unsigned int, bool) () at /usr/lib/libkwin.so.5
#8  0x00007f4e9ce161e0 in KWin::Workspace::createClient(unsigned int, bool) () at /usr/lib/libkwin.so.5
#9  0x00007f4e9ce925a8 in KWin::Workspace::workspaceEvent(xcb_generic_event_t*) () at /usr/lib/libkwin.so.5
#10 0x00007f4e9bcc295f in QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) () at /usr/lib/libQt5Core.so.5
#11 0x00007f4e938a2a92 in QXcbConnection::handleXcbEvent(xcb_generic_event_t*) () at /usr/lib/libQt5XcbQpa.so.5
#12 0x00007f4e938a382e in QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5XcbQpa.so.5
#13 0x00007f4e938cecce in  () at /usr/lib/libQt5XcbQpa.so.5
#14 0x00007f4e9bcc3b2c in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () at /usr/lib/libQt5Core.so.5
#15 0x00007f4e9bccbe36 in QCoreApplication::exec() () at /usr/lib/libQt5Core.so.5
#16 0x00007f4e9d24cb26 in kdemain () at /usr/lib/libkdeinit5_kwin_x11.so
#17 0x00007f4e9d0a3223 in __libc_start_main () at /usr/lib/libc.so.6
#18 0x0000557385bdf05e in _start ()
[Inferior 1 (process 1711) detached]

Possible duplicates by query: bug 400977, bug 390247.

Reported using DrKonqi